Static balancing machine



L. PETERSEN STATIC BALANCING MACHINE Dec. 28, 1943.

2 Sheets-Shet 1 Filed Nov. 22, 1940 h me m P m U lIllIlIIIIlIl/A HIS ATTORNEY 1943- L. PTERsEN 2,338,057

STATIC BALANCING MACHINE Filed Nov. 22, 1940 2 Sheets-Sheet 2- INVENTOR. v

- Louis Pefersen QZQQM/LA/ HIS ATTORNEY Patented Dec. 28, 1943 STATIC BALANCING MACHINE Louis Petersen, Detroit, Mich., assignor to Joseph P. Lannen Application November 22, 1940, Serial No. 366,599

9 Claims.

My invention pertains to mass centering apparatus and more particularly to work balancing machines for measuring and indicating the amount and location of the unbalance in a piece of Work or material which has been placed on the machine for testing.

It is an object of my invention to provide a mass centering machine of a simple rugged construction, which is convenient and economical to manufacture, maintain and use, and which provides accurate indications of the amount and location of the unbalanced mass of a piece of work centered thereon.

It is also an object of my invention to provide such a work balancing machine having an improved simplified universal mounting structure for the work supporting member.

It is a further object of my invention toprovide in such balancing machines an improved system =for producing conveniently observable manifestations for showing the amount and the location of the unbalanced mass in a piece of work centered on the machine for testing.

Another object of my invention is to produce such a testing machine of an improved simplified rugged construction eliminating relatively moving and frictionally engaging parts, pivots and the like which tend to introduce varying friction conditions, wear and misadjustment in the apparatus.

A further object of my invention is to provide a light beam indicating system cooperatively disposed in such a mass balancing system to provide conveniently observable magnified indications of the amount and location of the unbalanced mass of the piece of work being tested.

r rther objects and advantages are within the scope of my invention, such as relate to the arrangement, operation and function of the related eiements of the structure, to various details of construction, and to combinations of parts, elements per se, and to economies of manufacture and numerous other features as will be apparent from a consideration of the specification in conjunction with the drawings disclosing specific embodiments of my invention, similar reference characters being applied to corresponding elements throughout, and in which:

Fig. 1 is a plan View of my improved balancing machine;

Fig. 2 is a sectional View taken on line 2--2 of Fig. 1;

Fig. 3 is a sectional View taken on line 33 of Fig. 2;

Fig. 4 is an enlarged detail View taken on line 44 of Fig. 2;

Fig. 5 is an enlarged detail sectional view taken through the work support member and the universal mounting'thereof as indicated by line 5-5 inF'ig. 3; and

Fig. dis a diagrammatic View showing another simplified embodiment of the improved light beam indicating portion of the balancing machine.

Referring more particularly to Figs. 1 and 2 of the drawings, my improved mass centering machine comprises a stationary support or housing H for enclosing and supporting the elements of the apparatus. In accordance with usual practise, the housing has a pedestal flange I3 extending outwardly around the lower peripheral edge for securing the machine to the floor upon which it is mounted. The outer housing I I may be made of cast metal of any suitable shape for compactly enclosing the elements of the machine and the upper wall is provided with two apertures l5 and H for mounting the work support and the viewing screen in convenient adjacent relation.

Rising from the aperture I7 is a cylindrical shell or collar l9 having an outwardly projecting flange 2| around its lower edge which is secured to the housing by bolts or screws 23 passing down therethrough. Seated upon the upperedge of the sleeve I9 is a generally conical shaped member 25 having a laterally projecting flange 2!- around the upper edge for resting upon the upper edge of the sleeve, where it is secured as by screws 29 passing therethrough. An annular groove is provided in the inner edge of the upper side of the flange 21 on the cone for receiving and seating the peripheral edges of circular viewing screen 3|, and a retainin ring 33 is secured thereon by the bolts which pass down therethrough for securing the cone on the cylindrical sleeve. The conical member is substantially funnel shaped having a light projecting tube 35 opening and extending down into the housing from the apex.

For projecting light into the lower end of the tube 35 a light projector is positioned thereunder where it may be permanently mounted as by a. bracket 3'! projecting in from the side wall of the enclosing housing. The light projector may consist of a housing 39 enclosing an incandescent electric lamp M, of a type having a small or concentrated filament, and a tube 43 opening upwardly therefrom in alignment with the lower end of the tube 35 extending down from the, conical member. The lamp housing tube is provided with suitable light refracting means or lenses 45 for projecting the light upwardly in substantially annular ring 6 9.

tion while also having suitable "when an unbalanced load is placed thereon, to permit the ring to rotate accordingly, through a parallel rays to enter the lower end of the tube 35. Suitable lenses 6'3, t9 and bi are mounted in the tube 35, in a manner usual in optical practice. These lenses ll, A9 and 51! are suitably selected and spaced in the tube 35 for receiving and transmitting the parallel light rays received from the light source and iocussed for projecting a sharp index image upon the screen (ii at the upper end of the cone.

The screen Si is made of any suitable light transmitting material, preferably translucent, and has opaque gauging marks spaced apart thereon in such a manner that the movements of a light spot or shadow may be conveniently observed to determine the magnitude and the direction thereof. For this purpose the gauging marks on the screen preferably consist of a plurality of circular lines 53 of difierent diameters disposed concentrically in the manner in which targets are usually marked. n this arrangement, the magnitude of deflections originating at the center can be quickly and conveniently observed. To provide for observing precisely the direction of a deflection originating from the center, I provide also a plurality of straight line gauging marks 55 on the screen intersecting at the center and spreading radially therefrom in intersecting relation with the concentric lines. The light projected onto the screen is deflected or varied in accordance with the direction and the magnitude 'of the unbalanced mass of a piece of work being tested on my mass balancing machine in a manner to be subsequently described.

Mounted upon the edge of the other aperture l in the ST pporting housing I provide a stationary supporting ring 5i, as shown in Fig. 2, which is secured thereon in any suitable manner, as by screws 59 passing through into the housing. Movably mounted therein I provide an intermediate support member which may be in the form of an In order that the intermediate support ring ti may be mounted for relative movement in a compact rugged assembly it is made of a substantially smaller diameter than the outer support ring El and it is assembled in concentric relation therein. For movably mounting the intermediate support ring 65!, I provide a pair of lugs 63 which project outwardly from the ring in diametrically opposite directions. The

diametrically opposed lugs 83 are preferably of a Vertical thickness less than half of the vertical thickness or the intermediate support ring 61 and project from the lower portion of the ring. The stationary support ring 5? is also provided with a pair of lugs 65 projecting from the ring at diametrically opposite points and these project inwardly over the other lugs t3 which project outwardly from the intermediate support ring.

By also making the inwardly projecting lug 65 of a Vertical thickness less than half the thickness of the ring from which they project and by extending these inwardly from the upper portion of the ring, the two rings 5'5 and ill may be assembled together in a very compact assembly while 7 providing a small space between to permit rela-' tive movement, as may be seen in Figs. 2 and l.

As shown more clearl in Fig. 4, I provid extending vertically across the two adjacent lugs a thin ribbon El of steel, or other metal, having a suitable resilience to normally tend to hold the intermediate support ring 6! in a horizontal posiilexibility to bend small angle, on an axis passing horizontally through the two ribbons. The upper and lower ends of the ribbon are secured firmly to the adjacent respective lugs 65 and 63 by plates 69 clamped thereon as by screws or bolts ii. For this purpose a steel ribbon approximately $1 inch in thickness has proven satisfactory when the spacing of the lugs and the clamp plates are arranged to provide a bending length of the ribbon of about /1 0 inch. While the above mentioned dimensions of thickness and spacing have proven very satisfactory for testing work pieces within a certain range of sizes and shapes, it is to be understood that the thickness of the supporting ribbon and the spacing of the rings may be varied and the machine may be made larger or smaller for testing lighter or heavier work pieces.

In this arrangement th ribbon is tensioned for supporting the intermediate ring which is suspended from the stationary support.

A work support 13 is provided which is preferably of a generally circular or disk like conformation and of a diameter such that it may be mounted in concentric relation within th intermediate support ring GI and spaced slightly therefrom to permit fre movement. To mount the work support it, the intermediate ring 61 is provided with two notches or cut out portions 5 at diametrically opposed points in th under side and at right angles to the lugs projecting outwardly therefrom and previously described. One of the notches in the under side of the intermediate support ring may be seen in Fig. 2 over the top of and beyond the work support. The disk shaped work support '13 is provided with a pair of elongated lug ll which project outwardly therefrom in diametrically opposite positions, extending out through the notches it in the under side of the intermediate ring 8 l, and passing in spaced relation under lugs 19 which extend outwardly from the upper portion of the intermediate ring, as shown in Figs. 3 and 5. Two thin flexible ribbons 8i of metal pass vertically across the side of the adjacent upper and lower lugs Ti and i9 on opposite sides of the work support being clamped firmly to the lugs as by clamp plates 83 and bolts 85, in a manner similar to that previously described for th mounting of the intermediate ring on the stationary ring. The lugs H and '59 are so projected from the intermediate ring and the work support that these ribbons SI are suspended on a line passing through the center of the work support 13 so that this member will be balanced on its supports when not unbalanced by a work piece to be tested.

As shown in Figs. 1 and 2, a work table 8'! is provided for mounting work to be tested. The work table 8'! is of a circular disk shape and is provided with a hub 83 extending downwardly from the center of the lower side. The hub 89 has a conical downwardly converging surface having a suitable angular inclination to seat freely and without sticking into a conical socket provided in a hub 9! in th center of the work support iii. In the center of the upper surface of the test table an aperture or socket is provided suspended work support 13 while removing metal from the piece of work to be balanced or while moving work on or from the table, I provide a shaft 91, as shown in Fig. 2, which slides vertiaces- 057 cally through a pair of vertically spacedbearings 99 supported by bracketarms IOI projecting from the side walls of thehousing II. "The vertical shaft is positioned in central alignment with the work support table,-and the upper end is conically tapered for fitting into'the conical socket I03 provided in and opening downwardly from the center of thehub of the work table 81. The taper of the conical surfaces is selected suitably to avoid sticking of the shaft in the work table when it is lowered. For raising and lowering the shaft 91 conveniently at the wish of the operator, a shaft I05 is provided which extends horizontally and is journalled in a bearing bracket I'I extended between the two sliding bearings 99 and passes outwardly through the sidewall of the housing II in which it may be rotatably journalled in any suitable manner, as will be readily understood. The inner end of the shaft I is provided with an eccentric or cam I09 which is operatively disposed in a slot III in the side of the vertical shaft 91. As the shaft I05 is rotated by a crank H3 secured on the outer end of theshaft, the cam or eccentric I09 is rotated and the shaft91 is raised to lift the work table 81 from the flexibly suspended work support I3 while metal is being removed from or added to the piece of work to be balanced or while work is being installed on or removed from the testing machine.

When an unbalanced piece of -.work is placed on the mass balancing machine, the suspended work support 13 is caused to tilt on a horizontal axis passing through its suspending ribbons BI and it rotates through a small angle corresponding to the amount of the unbalanced moment about this axis. Butat the same time the intermediate support ring BI is caused to rotate through a small angle on an axis of rotation disposedat right angles to the first mentioned axis of rotation and passing through the ribbons 61 which support the ring, and the angular deflection of the ring BI corresponds to the unbalanced moment about this axis. To provide a measurement of th amount and position of the unbalanced. mass of the; work being tested indicating means is provided which producesa conveniently observable manifestation which varies in accordance with theabove described deflections of the suspended work support and the intermediate ring. For this purpose, an opaque index marker I I3 is provided, which may be a dot of opaque paint on a glass plate H5 although various and reversed arrangements may also be utilized. The glass plate H5 is mounted adjustably by spring clips Him a substantially horizontal strip HI having an'aperture H9 in alignment with the lower end of the optical tube 35 so that the light may normally pass therethrough onto the viewing screen 3| projecting a shadow of the index dot H3 on the center of the screen.

For moving the index dot H3 in accordance with'the direction and amount of the unbalanced mass of the work piece tobe indicated, one end of the strip II I is secured to the lower end of an arm I2I extending rigidly down from the movable work support l3, to which it may be secured as by a screw I23. The lower end of the arm I2I is preferably .bent parallel to the plane of the work support and extended laterally to, a position in alignment with the center or axis of the work support disk. The end of the armis secured to the adjacent: end of the index support strip II'I by means. of aflexible ribbon I25 secured between clamping plates I21 clamped together by screws I29. .The side of the intermediate support ring 0| adjacent the viewing screen is provided with a downwardly projecting bracket I3I, which may be secured thereto by a screw or Welding in any suitable manner. The ends of two arms I33 are clamped to opposite sides of the bracket I3I, as by a bolt I passing therethrough, and for firmly supporting the arms suitable notches may be provided on opposite sides of the bracket if desired. The two arms I33 pass around the viewing cone 25 toward the corners of the housing and are joined to gether through, a yoke I31 passing therebetween. Suspended from the extended ends of the arms I33 adjacent the corners of the housing is a light weight triangular piece I39, the corners of which are secured thereto through flexible suspension ribbons I secured at one end by bolts I M passing through clamp plates I43 into the ends of the arms. The other end of each ribbon is clamped between clamp plates I42 and secured to the corner of the triangle by bolts I44. The lower end or apex of the suspension triangle I39 converges toward the center line of the housing and is secured together by a bolt I45 which passes through two clamp plates I41 thus clamping the one end of a flexible ribbon I49 the other end of which is similarly secured to the adjacent end of the horizontal strip I II.

In this arrangement the deflections of the flexible suspended intermediate ring GI and the flexibly suspended work support I3 are cooperatively coordinated and applied to move the index marker I I3 to produce a proper manifestation on the screen in the manner previously described. The machine may be calibrated to indicate the amount of unbalance in inch ounces or any other units desired by the suitable selection of the distance of the center of gravity of the elements making up the swinging structure from the horizontal ribbon plane. To facilitate balancing the Work piece, marks 53' and 55' are provided on the work table corresponding to the marks on the screen 3I, and which may be observed between the spokes of a fly wheel or a tire supporting wheel, or around the peripheral edges of small work pieces, and the like. Calibration may also be accomplished in any customary manner of calibrating instruments, as by applying the marks on the screen in properly spaced positions, as will be understood. Differently calibrated screens are easily interchanged by removing the ring 33 shown in Fig. 2.

In Fig. 6, a simplified embodiment of the indicator operator means is diagrammatically represented. In accordance with this embodiment of my invention, the opaque index pointer H3 is carried directly on the arm I2I which projects rigidly down from the suspended work support 13. This is conveniently accomplished by providing clamping slot I5! in the end of the arm and inserting the transparent plate H5 therein which carries the index dot. The plate maybe secured in the arm by a bolt I53 passing through and clamping together the bifurcated end of the arm. In this embodiment the light source 39 is mounted above the index dot H3 and the light is projected downwardly therearound. Disposed under the index marker is a reflector or refractor I55 and an optical system comprisinglenses I51 and I59 and a second reflector or refractor ISI suitably spaced and enclosed as by interconnected tubes I63, I 65 and l G! for accurately transmitting the light variations from the measuring index and projecting upon the graduated screen 3| to produce visual manifestations of the measurements conveniently disposed, as in the first embodiment previously described. In this arrangerncnt a simplified construction is provided with a minimum of moving parts. in the first embodiment, the screen 3! is provided with suitably arranged and spaced marks for indicating both the direction of the position and the amount of the unbalanced mass in the work piece being tested on the machine. This arrangement may also be calibrated to produce the measuring indications in any desired units such as ounce inches or other suitable units. A counterweight IE8 is also secured to Work support 13 to compensate for the weight of the arm I2 I. If desired elongated flexible suspension members other than ribbons may be utilized. The bending points of the flexible suspension. members are disposed in a horizontal plane with the center of gravity of the swinging structure lower than thi plane for normally assuming a horizontal position of equilibrium.

It is apparent that within the scope oi the invention, modifications and different arrangements may be made other than herein disclosed, and the present disclosure is illustrative merely, the invention comprehending variations thereof.

I claim:

1. A static work balancer having in combination, a work support arranged to receive work to be centered thereon for balancing, a housing, mounting means in the upper wall of said housing for mounting the work support for universal tilting movement and tending to maintain the work support in a predetermined normal position, a light receiving screen disposed in the upper wall of the housing adjacent the work support, said screen having thereon gauging marks suitably dispo ed for showing the direction and magnitude of the deflections caused by the unbalanced condition of a piece of work on the til-table work support, an arm extending from the movable work support having an opaque index marker projecting laterally therefrom, a light source for projecting a beam of light downwardly around said opaque index marker, and an optical system arranged for transmitting the downwardly projected light beam upwardly to the screen for providing a conveniently disposed magnified manifestation on the screen adjacent the work support for measuring the unbalanced condition. of the work piece being tested.

2. In combination in a static balancing ma chine, a stationary support, an intermediate support ring having four supporting lugs projecting substantially radially at right angles forming two diametrically opposed pairs, a pair of supporting lugs projecting from said stationary support and spaced horizontally at a suitable distance to extend over two of the diametrically opposed lugs extending from the intermediate ring, a flexible ribbon secured to each stationary supporting lug, each flexible ribbon extending down from the attached stationary lug to the adjacent lug projecting thereunder from the intermediate ringdirections from said work'support-andextending in spaced relation under the other or free pair of diametrically opposed lugs projecting from the intermediate support ring, a flexible ribbon extending and secured between each Work support lug and the adjacent overlapping lug from the intermediate ring, a stationarily mounted gauging element, movable indicator means connected to said movable work support and extending therefrom for producing measuring manifestations adjacent said gauging element in accordance with the direction and degree of movement of the work support when an unbalanced piece of work is supported thereon.

3. A static balancing machine comprising, a stationary support, a work support adapted to receive work centered thereon for balancing, an intermediate support member, means mounting the intermediate support member on said stationary support for angular movement on a substantially horizontal axis, means mounting the work support on the intermediate member for angular movementon an axis substantially horizontal and at right angles to the axis of movement of said intermediate member, a marked light receiving screen, means for projecting light on the marked screen, a movable indicator index disposed in the light path to produce visual indications, and actuator means connecting from both the intermediate support member and the work support to said index for moving the index for producing indications of the amount and position of the unbalanced mass in a piece of work being tested on the machine.

l. In combination in a static mass balancing machine, a stationary support, an intermediate support ring having four support lugs projecting substantially radially at right angles forming two diametrically opposed pairs, a pair of supporting lugs projecting from said stationary support and spaced horizontally at a suitable distance to extend over two of the diametrically opposed lugs extending from the intermediate ring, a ribbon secured to each stationary supporting lug, each ribbon extending down from the attached stationary lug to the adjacent lug projecting thereunder from the intermediate ring for tensionally suspending the intermediate ring for angular rotation on a substantially horizontal axis, a Work support of a generally circular shape and of a suitable diameter relative to the ring to be supported in a substantially concentric position in the opening in the ring but sufficiently spaced therefrom for free relative movement, a pair of support lugs projecting in diametrically opposite directions from said work support and extending in spaced relation under the other or free pair of diametrically opposed lugs projecting from the intermediate support ring, a ribbon secured to each lug extending from the work support and secured to each adjacent lug of the intermediate ring for tensionally supporting the work support for angular movement on a horizontal axis substantially at right angles to the axis of movement of the intermediate ring, a stationary marked gauging element, a movable indicator cooperative with said gauging element for producing visual indications, actuating means extending from said intermediate ring to said indicatorv and actuating means extending from the work support to said indicator.

5. A static balancing machine comprising, a stationary support, a. work, support adapted to receive work centered thereon for balancing, an

intermediate support membenmeans mounting the intermediate support member on said stationary support for angular movement on a substantially horizontal axis, means mounting the work support on the intermediate member for angular movement on an axis substantially horizontal and at right angles to the axis of movement of said intermediate member, a screen of light transmitting material, said screen having thereon a plurality of spaced marks, a light source spaced from the screen for projecting light thereon, a movable index extending to a point in the path of the light traverse between the screen and the light source for producing magnified measuring manifestations on said screen in accordance with the amount and position of the unbalanced mass in a piece of work to be tested, and actuating elements extending to said index from the intermediate support and also from the work support so that the index is operated in accordance with a combined influence from both movable supports.

6. A static balancing machine comprising, a stationary support, a work support, an intermediate support member, means mounting the intermediate support member on said stationary support for angular movement on a substantially horizontal axis, means mounting the work support on the intermediate member for angular movement on an axis substantially horizontal and at right angles to the axis of movement of said intermediate member, indicator means responsive to movements of said work support, a work table adapted to receive and center work for balancing, a hub projecting down from the lower side of said table, said hub being of a downwardly converging conformation, a socket opening through the center of said work support and of asuitable conformation for receiving'and centering the hub of said work table therein, and-elevating means actuable for lifting said work table from the movable work support when work is to be changed on the table.

'7. A static balancing machine comprising, a stationary support, a work support, an'intermediate support member, means mounting the intermediate support member on said stationary support for angular movement on a substantially horizontal axis, means mounting the work support on the intermediate member for angular movement on an axis substantially horizontal and at right angles to the axis of movement of said intermediate member, indicator means responsive to movements of said work support, a work table adapted to receive and center work for balancing, a hub projecting down from the lower side of said table and having a socket opening in the lower end thereof, said hub having an outward shape which is downwardly converging, a socket opening through the center of said work support and of a suitable conformation for receiving and centering the hub of said work table therein, an elevating shaft, bearing means for slidably guiding said shaft in a vertical position in alignment with the center of the work support and table, and means for raising said shaft to insert the upper end into the socket in the hub and lift the work table from the movable work support member when work is to be changed on said table.

8. A static balancing machine comprising, a work support adapted to receive a work piece centered thereon for balancing, means mounting said work support movably to assume a substantially central and stationary position when unloaded or when supporting a balanced load, and universally tiltable to assume a different position in accordance with the unbalanced mass when supporting an unbalanced work piece, astationary light receiving screen, means for projecting light on said screen, and means extending from the universally tiltable work support into the path of the light for modifying the light on the screen to provide an amplified indication of the position assumed by the movable work support in accordance with the unbalanced mass in a piece to be tested.

9. In combination in a static balancing apparatus, a work support arranged to receive work to be centered thereon for balancing, a base having an upper wall, mounting means in the upper wall of said base for mounting the work support for universal tilting movement and tending to maintain the work support in a predetermined normal position, a light receiving screen disposed in the upper wall of the base adjacentthe worksupport, said screen having thereon gauging marks suitably disposed for showing the direction and mag-,

nitude of the deflections caused by the unbalanced condition of a piece of work on the tiltable work support, an arm extending from the movable work support and having an index marker projecting laterally therefrom, a light source for projectinga beam of light past said index marker, and an optical system arranged for transmitting the projected light beam on the screen for providing a conveniently disposed magnified manifestation on the screen adjacent the work support for measuring the unbalanced condition of the work piece being tested.

, LOUIS PETERSEN. 

